Is the hr relatively lower 10%-20% in version 18.22 during the running?

Similar.  My HR is 15% lower than prior to update.  It’s definitely a bug.  Halfway through a long run it randomly jumps up to normal rate. V18.22. 

Even in 18.23 HR seems to be lower at first. Despite that I'm experiencing another problem, with watch securely and tightly strapped to my wrist for at random times HR shows 50℅ lower than it should.

Same here on 18.23

So it's not just me...

I've already replaced my chest strap(H10) because i thought it was broken but it didn't help. I'm having weird dips with and without the strap. And i'm having a cadence lock with the new (original) strap(167bpm when i start the run). Never had this with any Garmin watch i owned. Even with a cheap strap.

I don't what they did but i don't like it

So you have the issue with a strap connected?

Are you other guys talking about wrist heart rate?

Same here.

Till 4 weeks I was running with a Forerunner 945 - my average HR for some similar runs (10km, about 45 minutes) was between 162 and 172 bpm.

Since I got the 965 I had 3 similar runs (10km, about 45 minutes). For the first two run I had an average HR of 160 and 161 (which seams to be ok). But after the software update to 18.22 (or even 18.23), I got an average HR of 132 bpm, which is a drop by more than 20%.

It's probably more than 10-20%. I updated because I thought the HR on 17.26 was way too high and this might fix it but I've seen it where I was in a moderate jog and my HR was not even 100. Should have been in the 120-125 range and was about 88. I had to stop and reboot and this seemed to clear it for a while but next time did the same thing.

Same here! I noticed I was taking longer to get to my desired heart rates for some runs and I was thinking, hey, my training has really kicked in in that I'm running much faster at a lower heart rate.

But nope, there was practically no movement in the HR before I was panting away and realised something's not right.

It's certainly not good for HR based training anyway.

Same problem: HR is all over the place. I need to reboot the watch often to get it working.

I reported it to support 2 days ago. They seemed to act like I was the only one with an issue. So, this is beginning to look like it's an across the board for everyone with the same symptoms. My 965 had been acting fine all morning but I just decided to go on a very brisk walk and didn't think to check my watch because it was reading 89 before I got going but lo and behold my heart rate was 80 about 8 minutes in. This firmware is trash! You really have no choice but to reboot the watch to get it working again.